The present invention relates to protective covers and, more particularly, to protective covers for distribution lines, such as power distribution lines, and methods for installing the same.
Support structures, such as utility poles, are often used to suspend electrical lines, such as power distribution lines, above the ground. These support structures are generally located outdoors and may be of a variety of different configurations to suspend one or more lines. One problem with such lines, particularly where the lines are power distribution lines that transmit electrical power at high voltages, is that birds or other animals may land or climb onto the lines. Such contact of distribution lines by animals, particularly adjacent the support structure, may result in a shock to the animal, possibly resulting in the death of the animal, if the animal causes a short or electrical flashover allowing current to flow through the animal.
For example, it is known that birds from time to time perch on support structures such as utility poles. For certain birds, their wing span is great enough to contact two parallel lines or otherwise create an electrical flashover during take off or landing. In addition, to harming the bird, such an electrical flashover can also cause a power outage or other problem with the power distribution system.
Various covers have been proposed to reduce the risk of electrical shorts at utility poles. For example, U.S. Pat. No. 5,873,324 describes a bird guard wire protector made of electrical insulating material. The protector has a central member sized and shaped to fit over the top of an insulator attaching a power wire to a support structure. The central member has a first connecting structure and a second connecting structure unitarily formed therewith and extending away therefrom. A first arm is connected to the first connecting structure to extend away therefrom and a second arm is connected to the second connecting structure to extend away therefrom.
Problems may be encountered with such unitary structure covers as the lines extending from the insulator at the support structure may extend from the insulator at different angles. Accordingly, it is known to heat such structures in the field so that they may be bent to a desired angle for attachment to a particular utility pole. However, this generally requires additional equipment and procedures, typically in the field, to prepare the cover for installation.
Embodiments of the present invention provide covers for distribution lines coupled to an insulator. Such a cover includes a main body of a flexible polymer material. The main body is configured to be positioned adjacent the insulator and a line coupled to the insulator. The adjacent position may be completely over or partially over and/or aside the insulator. At least one connector member is connected to the main body. At least one connector member is a rigid material as compared to the main body material and is configured to couple to the insulator and/or the line to attach the cover. In various embodiments of the present invention, the main body material has a tensile strength of less than about 2500 pounds per square inch (psi) and the at least one connector member has a tensile strength greater than the main body material and at least about 1200 psi. The flexible polymer material and the rigid material may be track resistant polymer materials
In further embodiments of the present invention, the main body includes a central portion configured to be positioned adjacent the insulator. A first line cover portion extends from the central portion and a second line cover portion extends from the central portion in a direction substantially opposite from the first line cover portion. The first and second line cover portions may also each include a corrugated portion adjacent the central portion that further increases rotational flexibility of the line cover portions relative to the central portion. The connector member(s) may be selected from the group consisting of a mechanical clamp, a displacement spring clip, a swinging clamp and a ratcheting clamp. In particular embodiments, the connector member(s) are displacement clip(s) molded into the main body. In some embodiments, the connector member(s) are coupled to the main body by fastener(s), such as threaded fastener(s).
In other embodiments of the present invention, an extender arm is coupled to the first line cover portion and extends from the central portion. The extender arm may be a rigid material and may be the same material as the connector member(s). In particular embodiments, at least one of the connector member(s) is a displacement clip and the extender arm and the at least one connector member(s) have substantially identical profiles, such as an omega profile. A second extender arm may be coupled to the second line cover portion and extend in a direction substantially opposite from the first line cover portion.
In further embodiments of the present invention, a releasable snap connector couples the extender arm to the first line cover portion. The snap connector may be a tab portion on an end of one of the first line cover portion and the extender arm and a corresponding opening on an adjacent end of the other of the first line cover portion and the extender arm. Alternatively, other type of connectors, such as fasteners, may be used to couple the extender arm to the line cover portion.
In other embodiments of the present invention one of the connector members is positioned in the first line cover portion to couple to a line extending from the insulator in a first direction and another of the connector members is positioned in the second line cover portion to couple to a line extending from the insulator in a second direction different from the first direction. A third connector member may be positioned in the central portion to couple to the insulator. The cover may further include an installation aid attachment portion in at least one of the main body and at least one connector member, the installation aid attachment portion being configured to engage an end of an installation aid, such as a hot stick, for installation of the cover on the distribution lines.
In further embodiments of the present invention, the rotational flexibility of the line cover portions accommodates a deviation of tip to about 25 degrees between an axis defined by a line extending from the insulator under the first line cover portion and an axis defined by a line extending from the insulator under the second cover portion. The line extending from the insulator under the first line cover portion and the line extending from the insulator under the second cover portion may be the same line, such as a power line passing by the utility pole and connected to the utility pole by an insulator.
In other embodiments of the present invention, methods are provided for covering distribution lines coupled to an insulator. A cover is provided comprising a main body of a flexible polymer material configured to be positioned adjacent the insulator and at least one connector member connected to the main body, the connector member being a rigid material. The cover is placed adjacent the insulator. An end of the main body is flexed to align with one of the distribution lines extending from the insulator. The connector member is connected to at least one of the insulator or the one of the distribution lines. Connecting the connector member may include connecting the connector member to the insulator. A connector member may instead or also be positioned in the end of the main body and connecting the connector member may include connecting the connector member to the one of the distribution lines.
In further embodiments of the present invention, a plurality of connector members are provided and flexing an end of the main body includes flexing a first end of the main body to align with a first line extending from the insulator in a first direction. A second end of the main body is flexed to align with a second line extending from the insulator in a second direction, different from the first direction. A first one of the connector members in the first end is connected to the first line and a second one of the connector members in the second end of the main body is connected to the second line. A third one of the connector members may be positioned in the main body and connected to the insulator.
In other embodiments of the present invention, an extender arm is connected to the first end of the main body. The extender arm is positioned to extend over the first line in the first direction. Another extender arm may be connected to the second end of the main body. The second extender arm is positioned to extend over the second line in the second direction.